Improved drill



UNITED STATES PATENT QEEIGE.

HENRY LOFTIE AND EGBERT YHINMAN, OF SYRAGUSE, NEW YORK.

IMPROVED DRILL.

Specification forming part of Letters Patent No. 51,065, dated" November'21, 1865.

To all whom it may concern;

Be it known that we, HENRY LOFTIE and EGBERT HTNMAN, of the city ofSyracuse, in the countyot'Onondaga and State ofNew York, have invented anew an d useful Improved Goni4 bination-Drill; and we do hereby declarethat the following is a full, clear, and exact description of theconstruction and operation of the same, reference being had to theannexed drawings, making a part of this specification.

Figures l and 2, side views; Fig. 3, end V1ew.

Letter a is the leading point of the combination-drill, extending belowthe other parts ofthe drill far enough so as to act as a guide to thedrill.

Letters b b are two drills, situated at right angles to said drill ct,placed central and at opposite sides of said drill a. Letter c isa drillat right angles with drill a and parallel withv drills b b.

Letter dis areanner parallel with the drills b b, the outside forming aportion ot' the circle of the diameter ot'the com binationdrills, theface ot' it being beveled from the eXtreme outside face, and may or maynot extend to the same point as the drills ci b b c. The points ofdrills b b c all are placed at an equal distance from the point ot' thedrill a, and the rearner d may or may not be placed at the same equaldistance from the point of drill a, all of said drills a b I) c andreanier d being formed and made ot and in one block of steel.

We construct our combination-drill out cfa piece or block of steel,forming the drills a b b c and reainer d of said piece or block of steelin the form and manner above described and in accordance with thedrawings hereto annexed.

Theopera-tion ot' our combination-drill is as follows: The centerdrill,a, is intended to start and guide the drills?) be and reainer d. Thedrill c, being parallel with the drills b b, as the coinbination-drillis rotated cuts at right angles with drills b b, and thereby cuts awaythe stone or material in which it is used with increased rapidity. Thereanier d is held in its proper place by drills a b b c, and as thewhole is rotated finishes the inside surface7 thereby making a true andperfectly round hole as fast as the combination-drill is forced downinto the stone by whatever motive power may be ap plied for thatpurpose.

What we claim as new, and desire to secure by Letters Patent7 is- The`cutters a and b, in combination with reamer d and cutter c, arranged inrelation to each other, substantially as described.

HENRY LOFTIE. EGBERT HINMAN. Witnesses:

W. M. BROWN, L. F. SMITH.

